What turbine choose? ~ 430 PS ~ 550 NM

[quattro84]

JD's Superflow is known for his dodgy dyno results.. it's a 'happy-dyno' on meeting occasions. He refuses people to map their car on his dyno with high HP potential for some reason.

[EspenW]

My last run was 314 whp, it was 353 engine hp.

That is a too low 11% drivetrain loss.
314 true wheel horsepower is what a quattro with close to 400hp at the crank will put down.

We know that the whp to chp relationship is off, problem is that we don't know if the whp or chp number is wrong. The whp number could be inflated, or the chp number could be underestimated.

[A80Avant]

Bram can already tell you about the spooling of the CT355 and the GT3071. It appears that the 3071 spools faster than the CT355 3bb,but obviously produces marginably less hp than that.

the best 3071 has given me is:3760rpm=500Nm/3900rpm=600Nm 4080rpm=620Nm on the same 3d gear pull
and 600Nm on 3400rpm on 4th gear pull.

on 5th and 6th gears it reaches 2bar from around 3000rpm.

if i had the patience to make the boost control more accurate with vems,then i could have a bit better results, but im bored.It tends to create a bit of a spike with the current settings so that's why on lower gears i get the boost a bit later.

[mk216v]

What A / R ratio of the gt3071? .63 Or .82

[A80Avant]

.63

[mk216v]

How much affect more power you get the .82 AR?

[Faheemo]

good spoolup ther.

dyno with 3071 0.63 AR Housing and 1.7bar boost, street map.
Go with the .82 AR housing - the .63 dies out on the top quickly.

[A80Avant]

im the last person to give you possible numbers and figures about what a turbo i havent tried, could to and perfom. Many people talk and suggest without own experience which may lead other to take the wrong decisions.

Only thing i can say,as Faheemo recommends is that the .82 AR will give some more top end power,but cannot say how much. I believe my 3071 with the adu cyl head and cams has been giving around 420hp and that is it's limit on this setup for me,as EGTs or timing are at their top end, and anything more than that would make the engine unsafe.

The torque is achievable in the low end with the 3071.Maybe the .82 will give you the edge to hold boost a bit longer and get a few more hp,but it will be on it's top limit. (unless you use different cams,in which case i have no idea of the results)